20% less speed, 50% less energy.
Saving energy with variable-speed drives
Rising energy costs and ambitious efficiency targets present operators of HVAC systems, pump systems, and industrial plants with a key question: Where can energy be saved without compromising comfort, process reliability, or system availability?
One of the most effective solutions is variable-frequency drives—provided they are used correctly.
Small reduction in speed, large reduction in power
Fans and pumps, in particular, offer enormous potential for savings. This is due to the physical relationships between speed, flow rate, pressure, and power consumption (affinity laws):
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Airflow ∝ Speed (n)
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Pressure ∝ Speed²
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Power consumption ∝ Speed³
In concrete terms, this means:
A speed reduction of just 20% can result in a power reduction of up to approximately 50%.
Variable-frequency drives enable precisely this demand-based adjustment—instead of running continuously at full power and “wasting” energy.
Why Vacon Variable Frequency Drives Are Ideal for HVAC and Pump Applications
In HVAC systems and pump applications, reliability, efficiency, and easy integration are key. Vacon variable frequency drives from Danfoss are particularly well-suited for these applications because they:
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offer excellent part-load performance
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include specially optimized pump and fan functions
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offer robust technology for a long service life
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can be flexibly integrated into existing systems
👉 Further information:
HVAC Fact Sheet
Fact Sheet Pumps
The key is the right approach—not just the product
Energy efficiency isn't achieved by a frequency converter alone, but through a well-thought-out overall concept. In practice, a clearly structured approach has proven effective:
1. Analysis
Recording load profiles, operating times, motor power, and actual demand.
Only those who know how a system is actually operated can identify the true savings potential.
2. Interpretation
Selecting the right combination of motor and frequency converter—tailored to the application, control strategy, and efficiency. Factors such as EMC, part-load performance, and future-proofing also play a role here.
3. Commissioning
Proper parameterization, precise control, and documented measurements ensure that the theoretical savings are realized in actual operation.
4. Operation
Maintenance, condition monitoring, and—where appropriate—retrofit or replacement strategies extend service life and ensure low operating costs over the long term.
